'Perfect storm' delivers

If you frequent the slopes of Whitefish Mountain Resort and you weren’t there on Sunday, you’ve probably heard all about it by now.

Feb. 26 arrived with 11 fresh inches of fluffy powder at Big Mountain’s summit, according to the resort’s snow report that morning, followed by a day-long dump of unusually dry flakes that kept skiers and snowboarders whooping for joy. About 18 inches of grade-A cold smoke had piled up by the end of the day.

Steady snowfall this week pushed the mountain over the 300-inch mark on Wednesday, putting this winter on track to be the fourth-heaviest snow year in the last two decades, according to the resort’s records.

A Thursday press release from the resort stated that more than nine feet of snow fell at the summit last month — the deepest February total in a decade. As of March 1, the 307-inch total for the season put it just 13 inches behind the historic snow year during the winter of 1996-97, but several feet shy of the March 1 total from the 2007-08 season. That winter ended with 426 inches — the resort’s highest snow total in the last 20 years.

The resort also made note of Sunday’s standout conditions, echoing many long-time local skiers who placed it as one of the top powder days in recent memory. Late-season tourists also marveled at the seemingly bottomless supply of nearly weightless powder.

“I’ve been riding with a couple people today that said it was the best powder day in five years,” said Cody Morton, who flew into Montana from Stratton, Vermont on Saturday to spend a week hitting the slopes with a group of friends living in Whitefish. “It’s been epic.”

Compared with the wetter, heavier snow back home, he analyzed the “epic” powder day with expletive-laden adulation.

“... It’s much lighter and fluffier, the temperature was beautiful, with not as much wind,” Morton said. “It’s so easy to just cut through and get lost.”

Locals also noted that beyond the depth, snow conditions were atypical for Big Mountain, which normally sees denser snowfall than the dry, light flakes common in higher-elevation parts of the Rocky Mountains.

Erich Peitzsch, a physical scientist with the U.S. Geological Survey and former director of the Flathead Avalanche Center, said snow surveys in this part of the Rockies typically find densities of around 10 percent snow-water equivalent. That’s good, light snow compared to coastal climates, he said, where higher atmospheric moisture tends to produce denser snow.

After measuring the density of snowfall from Sunday’s storm, however, Peitzsch said it was around 5 percent snow-water equivalent.

“If you take a volume of snow, five percent of that would be water and the rest would be air,” he said. “That’s why it’s so fluffy and nice and fun to ski. And it was so deep that people were choking on it.”

Farther inland than the Sierra Nevadas and the Cascades, which are known for receiving wetter, ocean-fed snowstorms, Northwest Montana is spared much of the atmospheric moisture that results in denser snow. But elevation plays a key role in producing the drier, colder climates that produce the ultra-light powder common to ski areas in Colorado and Utah.

Peitzsch said that Northwest Montana’s cold snaps, like those that dropped temperatures into the double-negatives earlier this year, are often part of drier weather systems. But the storm system that rolled through last weekend hit while the mercury plunged into the single digits overnight.

“During those cold periods, it just didn’t precipitate” earlier this winter, he said. “But this was pretty perfect conditions, and for skiers, for snowboarders, for snowmobilers, it was sort of the perfect storm.”

Reporter Sam Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.